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Climate Change, Excess Land–Uses and Farmers’ Water Demand: An Induction from Smallholder Farms of Muooni Dam Site, Kenya

24-36Full Text

Cush L. NGONZO*, Chris A. SHISANYA and Joy A. OBANDO

Abstract
Abstract: Erratic rainfalls, heavy winds pressure and erosional processes due to El Niño floods and droughts are major causes of as farmlands degradation in the catchment, as well as Muooni dam siltation and its water storage capacity decrease. Beside, bad land management associated with excess multiple cropping of eucalyptus and other alien trees in the wetlands, as well as farmlands subdivision hampers water availability in the catchment. Put altogether, these factors affect at least 61% of the total variation of Muooni dam‟s active water storage capacity. They result in higher water shortage costs and lower yields in farming threatening significantly the efficiency of farming activities in the catchment. This, combined with other socio-economic factors, explains farmers‟ poverty and food insecurity therein. To improve the economic viability of their activities, farmers need to optimize their crops water requirement using efficient hydro-political strategies, on-farm land management techniques and technological innovation. The government shall effectively implement land allocation and water consumption metering mechanisms in Muooni catchment to ensure equity. Keywords: Climate, Land–Uses, Water Demand, Smallholder Farms.

Applied Inventory Models for Evaluating Water and Food Security: Approaches and Lessons from Smallholder Farms of Muooni Catchment, Machakos District, Kenya

37-45Full Text

Cush NGONZO LUWESI*, Chris Allan SHISANYA and Joy Apiyo OBANDO

Abstract
Abstract: This study attempts to explain food shortage in a water scarce Muooni catchment using operational research inventory models. It seeks specifically to evaluate farmers‟ water economic order quantity (EOQ), limit average cost (LAC) and minimum efficient scale (MES) of water use in farming, for rationalization and optimization of crops water requirement and crops yields under rainfall fluctuation. Such an approach helps integrating spatially distributed and descriptive mathematical variables of water storage with economic performance and environmental sustainability. Results show that Muooni dam siltation and subsequent water stress threatens the economic viability of smallholder farms in the catchment. Both endogenous on-farm management factors and exogenous environmental agents hamper the rate of fertile soil loss and water stress under rainfall fluctuation. They increase significantly the costs of costs water saving and shortage costs in farming, threatening agriculture economic viability and food security. For efficiency, farmers need to define a water demand EOQ under ANOR, or a quantity well-matched with the LAC under NOR, or a MES quantity under BNOR in order to optimize their crops water requirement. This means that they need to implement rational methods of water use in farming and appropriate farming technologies to foster allocative and technological efficiencies within the production possibility frontier. Also, the government should implement a catchment management strategy (CMS) in Athi catchment in general, and Muooni in particular, to mitigate the risk of food shortage and water conflicts under unexpected drought.This study attempts to explain food shortage in a water scarce Muooni catchment using operational research inventory models. It seeks specifically to evaluate farmers‟ water economic order quantity (EOQ), limit average cost (LAC) and minimum efficient scale (MES) of water use in farming, for rationalization and optimization of crops water requirement and crops yields under rainfall fluctuation. Such an approach helps integrating spatially distributed and descriptive mathematical variables of water storage with economic performance and environmental sustainability. Results show that Muooni dam siltation and subsequent water stress threatens the economic viability of smallholder farms in the catchment. Both endogenous on-farm management factors and exogenous environmental agents hamper the rate of fertile soil loss and water stress under rainfall fluctuation. They increase significantly the costs of costs water saving and shortage costs in farming, threatening agriculture economic viability and food security. For efficiency, farmers need to define a water demand EOQ under ANOR, or a quantity well-matched with the LAC under NOR, or a MES quantity under BNOR in order to optimize their crops water requirement. This means that they need to implement rational methods of water use in farming and appropriate farming technologies to foster allocative and technological efficiencies within the production possibility frontier. Also, the government should implement a catchment management strategy (CMS) in Athi catchment in general, and Muooni in particular, to mitigate the risk of food shortage and water conflicts under unexpected drought. Keywords: Applied Inventory, Evaluating, Food Security.

Hydro-economic inventory for sustainable livelihood in Kenyan ASALs: The case of Muooni Catchment

46-55Full Text

Cush Ngonzo Luwesi*, Chris Allan Shisanya, Joy Apiyo Obando

Abstract
Abstract: South-East Kenya is vulnerable to increased siltation and pollution of drainage channels and dams as well as to high risk of crop failure under fluctuation of rainfall regimes. This increases the cost of water for the production of food and energy supply. A study conducted in Muooni Dam Catchment shows that both anthropogenic factors and environmental externalities perturb efficient use of water by farmers in the dam site. Land-use activities going on in Muooni Dam Catchment along with El Niño floods and droughts have an impact on the active water storage capacity of Muooni Dam. Under the effects of farmland degradation and the trade effects of the global climate change, they have resulted in relentless changes of the catchment microclimate. This study reveals that these factors have affected water availability in Muooni Dam at a decreasing rate of 6.2% per year. The latter thwarts any prospect of high yields and good incomes among smallholder farms, and hampers sustainable supply of bio-energy and hydro-electricity. Due to increased farming water costs and high crop water requirements, farmers use excessive multiple cropping to cope with water stress and poor incomes. They often substitute staple crops by eucalyptus and other alien trees to avoid high risk of crop failure. For efficiency, farmers were urged to adopt an “Economic order quantity (EOQ) or a “Limit average cost” (LAC) or at least a “Minimum efficient scale” (MES) of their water demand under the above normal (NOR), normal (NOR) and below normal (BNOR) rainfall regimes, respectively, using efficient farming technologies and hydro-political strategies. “Hydro-economic inventory” is thus a prerequisite for implementation of an «Integrated watershed management» to ensure sustainable food production and energy supply. Keywords: Climate change, Economic inventory, Hydro-geomorphologic impact assessment, Land degradation, Social impact assessment, Water use efficiency.

Hydro-Economic Inventory Models for Planning and Evaluation of Farming Water Efficiency in a Semi-Arid Watershed of Kenya

56-62Full Text

Cush NGONZO LUWESI*, Chris Allan SHISANYA and Joy APIYO OBAND

Abstract
Abstract: Water scarcity and its unsustainable use are threatening farming efficiency in most “Arid et semi-arid lands” (ASALs) of Kenya. More significantly, these factors lead to recurrent food shortage in Machakos District of Kenya. This has been attributed to both endogenous and exogenous factors pertaining to on-farm management and environmental changes, respectively. This study used hydro-geomorphologic risk assessment, social impact and economic inventory models to evaluate farmers‟ water use efficiency. This procedure referred to as “hydro-economic inventory” assesses the risks related to the use of water and land in farming, and its impact on the social welfare of farmers and the economic viability of their activities. It serves as a basis to the planning, monitoring and evaluation of water disasters in agriculture in that catchment area. It focuses on an incremental analysis of crop water requirements and farmers‟ water demand under fluctuating rainfall regimes using hybrid inventory models. Results of this study show that significant increase of water shortage costs under below normal rainfall regime (BNOR) undermines agricultural efficiency. Almost all farming units need to define a “Minimum efficient scale” (MES) of their farming water demand to optimize their crop water requirements under recurrent risk of drought. Farmers also need appropriate farming technologies and rational water policies to foster their economic efficiency. Keywords: hydro-economic inventory, crop water requirement, climate change, farming water optimization.

Essentials for Implementation of Improved Green Water Management in Muooni Catchment, Machakos District of Kenya

63-70Full Text

CUSH NGONZO LUWESI*, ESAM BADER

Abstract
Abstract: Global climatic, demographic and economic changes affect ―blue water‖ accessible in streams, lakes and groundwater under the effects of deforestation. Yet, two thirds of water resources referred to as ―green water‖ are retained by plants for their own use. Their depletion has an impact on agricultural lands productivity. There is thus need for managing skilfully green water. A study conducted in Muooni Catchment of Kenya assessed the need for Green Water Saving (GWS) in that area and its value-addition to the supply of crop water requirement. This paper illustrates the use of operational research to simulate the ―Economic Order Quantity‖ (EOQ) and to cost green water supply in Muooni Catchment of Machakos District, in Eastern Province of Kenya. Results show that farmers‘ water demand is more than their crop water requirement. They tend to use inefficient cropping methods and water management techniques that significantly increase their farming water losses. Considerable investments in GWS are thus needed to increase by at least 50% the one-tenth accessible blue water, and foster a green revolution in ASATs in general, and Muooni Catchment in particular. This may prevent water disasters and crop failures, as well as alleviate farmers‘ poverty in these areas. Keywords: Green water saving, Crop water requirement, Economic order quantity (EOQ), Farmer’s water demand, Integrated watershed management (IWM), Rainfall fluctuation.